# if 条件
a, b = 1, 2
if a == 1 or b == 2:
    print("right")

# in 判断
banned_users = ['andrew', 'carolina', 'david']
user = 'marie'
if user in banned_users:
    print(f"{user.title()}, you can post a response if you wish")
print(len(banned_users))
# 布尔表达式
game_active = True

# if elif else
age = 12
if age < 4:
    price = 0
elif age < 18:
    price = 25
elif age < 65:
    price = 40
else:
    price = 20

print(f"Your admission cost is ${price}.")